Rotary digital contacting encoders or rotary pulse generators are known, in which a cog-type conductive pattern is provided on an insulating substrate, to which three external electrical connections are selectively made and over which a "U" shaped, bridging, wiping contact is rotated. As the "U" shaped contact is rotated, it alternately connects a common pin or connection (for example, pin "2") for a limited period of time to one and then the other of the other two connections (namely, the remaining pins "1" & "3"), alternately and sequentially making bridging interconnection between the common pin and one of the other pins, producing digital-type, pulsed electrical signals across the pins, having the wave forms shown in FIG. 8 hereof.
The cog pattern in such devices typically includes two, concentric cog rings with generally opposed, alternating cogs, as shown in detail in FIG. 7 hereof, and are quite small and fine in their design. They involve gaps between the generally opposed, radially extended cogs of, for example, only fifty-five ten-thousandths (0.0055") of an inch with a ring width of, for example, only thirty-nine thousandths (0.0039") of an inch.
The cogs of the rings are either directly opposed, as, for example, is shown in U.S. Pat. No. 4,443,670 of Nakamura et al issued Apr. 17, 1984, or somewhat staggered or axially off-set, as shown in FIG. 7 hereof.
In the manufacture of such devices in the prior art, the electrical connections to the concentric rings were directly made to them, usually peripherally as shown in the '670 patent, resulting in the need for relatively precise alignment and positioning of the electrical connections with the rings, with very little tolerance being allowed, causing manufacturing problems and difficulties.
The present invention is designed to avoid these manufacturing problems and difficulties.